Folium Choropleth，pandas 的问题：GeoJSON 引发 AttributeError：'NoneType'

Question

我正在使用 Folium 对数据框进行数据可视化，但我坚持在 Folium 中设置 Choropleth 地图的 key_on 参数。 可以查看example code snippet on gist here

我的geojson：

{
    "type":"Topology",
    "arcs":[...],
    "transform":{...},    
    "objects":
        "Com01012018_g_WGS84":{
            "type":"GeometryCollection",
            "geometries": [
                {
                    "arcs":[...],
                    "type":"Polygon",
                    "properties": {
                        "COMUNE": "Borgo Vercelli",
                        "PRO_COM": 2017,
                        ...
                    }
                },
                {...},
            ]
        }
}

我的熊猫 df：

id     comune                  a11y-score   
0   Aquila d'Arroscia           65.17
1   Castel del Rio                 68.75
2   Castellaneta                 71.95
3   Castelvetrano                 77.27
4   Montescudo-Monte Colombo    59.65

我想在“COMUNE”上设置键，我可以很容易地遍历geojson：

with open('italy-comuni.json', encoding='utf-8') as json_file:
    data = json.load(json_file)
    obj = data['objects']
    for righe in obj["Com01012018_g_WGS84"]['geometries']:
        print(righe['properties']['COMUNE']) #print the name of the City

按照 OP here 的建议，我检查了这个 json 和我导入的数据帧是否具有相同的“comune”值（以避免提高 KeyError ）并且 a11y-score 中的值已填充（从 0 到 100 的浮点值)。

这是我的传单代码：

m = folium.Map(location=[42.833333, 12.833333],zoom_start=6,tiles="Mapbox Bright")
m.choropleth(
 geo_data=state_geo,
 name='choropleth',
 data=italia_df,
 columns=['comune', 'a11y-score'],
 key_on='object.geometry.properties.COMUNE',
 fill_color='YlOrRd',
 fill_opacity=0.7,
 line_opacity=0.2,
 legend_name='A11y Score'
)
folium.LayerControl().add_to(m)

无法弄清楚如何正确设置 key_on。 尝试了这些，但实际上没有任何效果：

object.geometries.properties.COMUNE
objects.geometries.properties.comune
objects.Com01012018_g_WGS84.geometry.Polygon.properties.COMUNE
objects.Com01012018_g_WGS84.geometries.Polygon.properties.COMUNE
objects.geometry.Polygon.properties.COMUNE
objects.geometries.Polygon.properties.COMUNE
object.geometries.Polygon.properties.COMUNE
Com01012018_g_WGS84.geometry.properties.COMUNE

错误：

---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
<ipython-input-19-578cc4d527b5> in <module>()
      1 # Save to html
----> 2 m.save('italy-a11yscore.html')

~\Anaconda3\envs\py36\lib\site-packages\branca\element.py in save(self, outfile, close_file, **kwargs)
    159 
    160         root = self.get_root()
--> 161         html = root.render(**kwargs)
    162         fid.write(html.encode('utf8'))
    163         if close_file:

~\Anaconda3\envs\py36\lib\site-packages\branca\element.py in render(self, **kwargs)
    307         """Renders the HTML representation of the element."""
    308         for name, child in self._children.items():
--> 309             child.render(**kwargs)
    310         return self._template.render(this=self, kwargs=kwargs)
    311 

~\Anaconda3\envs\py36\lib\site-packages\folium\map.py in render(self, **kwargs)
    336             '</style>'), name='map_style')
    337 
--> 338         super(LegacyMap, self).render(**kwargs)
    339 
    340 

~\Anaconda3\envs\py36\lib\site-packages\branca\element.py in render(self, **kwargs)
    622 
    623         for name, element in self._children.items():
--> 624             element.render(**kwargs)

~\Anaconda3\envs\py36\lib\site-packages\branca\element.py in render(self, **kwargs)
    618         script = self._template.module.__dict__.get('script', None)
    619         if script is not None:
--> 620             figure.script.add_child(Element(script(self, kwargs)),
    621                                     name=self.get_name())
    622 

~\Anaconda3\envs\py36\lib\site-packages\jinja2\runtime.py in __call__(self, *args, **kwargs)
    573                             (self.name, len(self.arguments)))
    574 
--> 575         return self._invoke(arguments, autoescape)
    576 
    577     def _invoke(self, arguments, autoescape):

~\Anaconda3\envs\py36\lib\site-packages\jinja2\asyncsupport.py in _invoke(self, arguments, autoescape)
    108     def _invoke(self, arguments, autoescape):
    109         if not self._environment.is_async:
--> 110             return original_invoke(self, arguments, autoescape)
    111         return async_invoke(self, arguments, autoescape)
    112     return update_wrapper(_invoke, original_invoke)

~\Anaconda3\envs\py36\lib\site-packages\jinja2\runtime.py in _invoke(self, arguments, autoescape)
    577     def _invoke(self, arguments, autoescape):
    578         """This method is being swapped out by the async implementation."""
--> 579         rv = self._func(*arguments)
    580         if autoescape:
    581             rv = Markup(rv)

<template> in macro(l_1_this, l_1_kwargs)

~\Anaconda3\envs\py36\lib\site-packages\jinja2\runtime.py in call(_Context__self, _Context__obj, *args, **kwargs)
    260                 args = (__self.environment,) + args
    261         try:
--> 262             return __obj(*args, **kwargs)
    263         except StopIteration:
    264             return __self.environment.undefined('value was undefined because '

~\Anaconda3\envs\py36\lib\site-packages\folium\features.py in style_data(self)
    563 
    564         for feature in self.data['features']:
--> 565             feature.setdefault('properties', {}).setdefault('style', {}).update(self.style_function(feature))  # noqa
    566             feature.setdefault('properties', {}).setdefault('highlight', {}).update(self.highlight_function(feature))  # noqa
    567         return json.dumps(self.data, sort_keys=True)

~\Anaconda3\envs\py36\lib\site-packages\folium\folium.py in style_function(x)
    303                 'color': line_color,
    304                 'fillOpacity': fill_opacity,
--> 305                 'fillColor': color_scale_fun(x)
    306             }
    307 

~\Anaconda3\envs\py36\lib\site-packages\folium\folium.py in color_scale_fun(x)
    290             def color_scale_fun(x):
    291                 return color_range[len(
--> 292                     [u for u in color_domain if
    293                      get_by_key(x, key_on) in color_data and
    294                      u <= color_data[get_by_key(x, key_on)]])]

~\Anaconda3\envs\py36\lib\site-packages\folium\folium.py in <listcomp>(.0)
    291                 return color_range[len(
    292                     [u for u in color_domain if
--> 293                      get_by_key(x, key_on) in color_data and
    294                      u <= color_data[get_by_key(x, key_on)]])]
    295         else:

~\Anaconda3\envs\py36\lib\site-packages\folium\folium.py in get_by_key(obj, key)
    286                 return (obj.get(key, None) if len(key.split('.')) <= 1 else
    287                         get_by_key(obj.get(key.split('.')[0], None),
--> 288                                    '.'.join(key.split('.')[1:])))
    289 
    290             def color_scale_fun(x):

~\Anaconda3\envs\py36\lib\site-packages\folium\folium.py in get_by_key(obj, key)
    285             def get_by_key(obj, key):
    286                 return (obj.get(key, None) if len(key.split('.')) <= 1 else
--> 287                         get_by_key(obj.get(key.split('.')[0], None),
    288                                    '.'.join(key.split('.')[1:])))
    289 

AttributeError: 'NoneType' object has no attribute 'get'

我还找到了another question on this problem，但在那里找到的解决方案对我不起作用。我正在努力在key_on 参数中找到正确的组合。

感谢您的帮助！

更新我已经更改了我的 JSON，它现在看起来像这样：

{ "type":"FeatureCollection", 
"features":[ 
             "type":"Feature", 
             "geometry": {...}, 
             "properties": { 
                    "comune": "Borgo Vercelli", 
                    "PRO_COM": 2017, 
                     ...

但我无法使用 feature.properties.comune 遍历它。在地图中我看不到我的 GeoJson 图层。

Answer 1

folium.Map.choropleth (read it on GitHub here) 的文档字符串表明 key_on 参数是一个必须始终以 'feature' 开头的字符串。所以我要尝试的第一件事是：

key_on='feature.properties.COMUNE'

Answer 2

我有“AttributeError”，但是当我添加时它消失了

tiles="OpenStreetMap"

我的 folium.Map() 声明。

Answer 3

对我有用的是设置“key_on=”的键名从“feature.xyz.abc”开始，而 json 文件中的实际键等于“features”

实际：

`m.choropleth(
 geo_data= gsonfile,
 name='choropleth',
 data=pd_total,
 columns=['Neighbourhood', 'Count'],
 key_on= 'feature.properties.DISTRICT',
 fill_color='YlOrRd',
 fill_opacity=0.7,
 line_opacity=0.2,
)`

JSON：

`{
  "type": "FeatureCollection",
  "crs": {
    "type": "name",
    "properties": {
      "name": "urn:ogc:def:crs:OGC:1.3:CRS84"
    }
  },
  "features": [{
    "type": "Feature",
    "properties": {
      "OBJECTID": 1,
      "DISTRICT": "CENTRAL",
      "COMPANY": "A"
    },`